October 4-8, 2011

Cambridge & Woburn, MA

Bruce Gary has announced a one-month pilot project to evaluate the feasibility of observing exoplanet transits of white dwarfs. The advantage of looking at white dwarfs is that the eclipses will be deeper. The disadvantage is they will be very short (on the order of minutes). So there is considerable challenge here!

The Be stars

Be-ness is not only an evolutionary stage in the lives of some rapidly rotating hot B-type stars but also a transient phenomenon that may come and go over the years for the same star. Several reasons have been proposed to explain the behavior of these stars and are still in debate.

June 30, 2011: Since its outburst on 2011 April 14 (see AAVSO Alert Notice 436), the recurrent nova T Pyx has been very well monitored by visual and instrumental observers who can reach -32o. Thank you! Currently T Pyx is visual/V magnitude ~8.3.

A complete light curve of this eccentric (~2.094d) eclipsing binary system has been determined, in B, V, and R bands. The primary and secondary minima are slightly different in depth, and the color index does not change during either primary or secondary eclipse. Newly-determined times of minimum confirm the previously-suspected rapid change in the orbital phase of the secondary minimum, implying significant apsidal motion.

Hi, all. Today we rolled out some relatively minor upgrades to VSP. There is nothing groundbreaking here. It's mostly minor tweaks and bug fixes. But I'm outlining them here for your information:

Additions
- There is a new "reset all" button that will reset all fields in the user interface to their default values.
- The variable star designator (cross hairs at the center of the chart) now appears on all charts, regardless of the limiting magnitude.

Better magnitudes and epochs have been determined for 189 of the 379 confirmed and suspected variable stars discovered by Ross from 1925 to 1931. Accurate positions have been determined for those objects for which unambiguous identifications had been lacking.

Michael Poxon has taken it upon himself to head a new AAVSO section on his favorite class of variable star: Pre-Main Sequence Stars (YSO/PMS). The AAVSO has had a long history of working with such objects, especially the "Orion variables" that were monitored by many visual observers for years.

July 21 Update: The books are here! The AAVSO has 100 copies of the book that we are selling at the same Cambridge Press discounted rate of $80. So please order from the AAVSO store and help support the organization. We have the books in stock for immediate shipment.

June 3, 2011: As an update to AAVSO Special Notice #241 (http://www.aavso.org/aavso-special-notice-241), the supernova in M51 has been designated SN 2011dh. Discovery, classification, and observation information have been published in IAU CBET 2736 (Daniel W. E. Green, ed.).